1. Field of the Invention
The present invention relates to a light emitting diode (LED) voltage driver circuit, and more particularly, to a driver circuit which provides a voltage to an LED.
2. Description of Related Art
Recently, light emitting diode (LED) lighting has emerged as a promising market in a lighting industry in South Korea. Interest in LED lighting has significantly increased as a way to save power in advanced countries as well as due to last year's large earthquake in Japan and the nuclear power plant accident in Fukushima. LED lighting companies in South Korea are actively achieving related certifications in every foreign country to preempt overseas markets, and there is a growing trend of introducing new LED lighting products which added sensibility and various functions that are difficult to realize with conventional fluorescent lamps to the market as well as LED lighting demands for replacing conventional fluorescent lamps.
When a voltage applied to an LED is equal to or more than a threshold voltage of the LED, a current starts to flow through the LED so that light is emitted therefrom. Low-voltage direct current (DC) power is supplied to drive such an LED using a battery, a power supply, or the like.
A power supply is mainly used as a device for supplying low-voltage DC power, and such a power supply receives commercial alternating current (AC) power, converts the AC power into predetermined DC power, then converts the predetermined DC power into LED driving power, and supplies the LED driving power to an LED.
When an LED is driven by a conventional power supply, commercial AC power is converted into a predetermined DC power to drive the LED.
Some methods such as controlling an output of a transformer to be a constant current output for lighting an LED, using a constant current circuit at an output terminal of the LED, using a boost circuit and a constant current circuit, or the like are frequently used as methods for controlling an LED, however, such a conventional control method has a problem in that power conversion efficiency is lowered and the circuit is complicated.
Therefore, an LED voltage driver circuit technology capable of efficiently supplying power to an LED needs to be provided.